Construction and sequence analysis of a drought-induced full-length cDNA library from Ammopiptanthus mongolicus / 生物工程学报

Ammopiptanthus mongolicus shows very strong resistance to severe environments. To isolate drought-resistant genes and elucidate drought-resistant molecular mechanisms of the plant, we constructed a drought-induced full-length cDNA library using SMART (Switching mechanism at 5'-end of RNA transcript) technique. The phage titer of the unamplified library was 1.6 x 10(7) PFU/mL; the recombination percentage was 97.7%; and the sizes of most cloned cDNA fragments were around 1 kb. Three thousand positive clones were randomly selected and sequenced from their 5' ends, and a total of 1 450 Unigenes were identified. By Blast searches against the Nt, Nr and Swissprot databases, we found that 919 Unigenes (amount to 63.4%) showed significant similarity to the annotated genes, and the remaining 531 Unigenes (amount to 36.6%) represented novel genes without any annotation. Among the functional categories of the GO (Gene Ontology) classification, the terms related to physiological process, cellular process, binding, catalytic activity and cellular components were dominant. The next abundant terms were for organelle, protein complex, transporter activity and structural molecule activity. In addition, there were a significant proportion of the terms involved in stimulus response, gene expression regulation, regulation of physiological and biochemical processes and signal transduction. Many of the annotated Unigenes were found to be related to plant resistance to abiotic stresses, and expression analyses of 6 out of these genes by semi-quantitive RT-PCR confirmed their involvements in the response of A. mongolicus to drought stress. These results laid a foundation for the expression profile analysis and the cloning and characterization of drought-resistant genes from the plant in the future.

Expression and Significance of ER, PR, C-erbB-2, CylinD1, Rb in Different Precancerous Lesions of Breast / 中国基层医药

ObjectiveTo explore the expression and significance of ER, PR,C-erbB-2,CylinDl, Rb in different precancerous lesions of breast. MethodsThe expressions of ER, PR, C-erbB-2, CylinD1, Rb in breast normal tissue,hyperplasia, atypical hyperplasia and early-stage breast cancer were examined by immunohistochemical technique. ResultsThe expressions of ER and PR were increasing time trend in the different precancerous lesions, and were related to the breast proliferative degree; the positive expression rates of ER and PR in atypical hyperplasia were 63.2% and 68. 4% respectively,significantly higher than those in normal breast tissue(31.3% and 37. 5% respectively) and in hyperplasia(37. 1% and 42.9% respectively). The positive expression rates of CylinD1 and C-erbB-2 were increasing time trend in the different precancerous lesions. The negative expression rate of Rb was the highest in early-stage breast cancer,and it was zero in normal breast tissue and hyperplasia. ConclusionThe five tumor markers are important factors in breast carcinogenesis, and the overexpression of ER, PR, C-erbB-2, CylinD1 and Rb protein low-expression may be one of the causes of breast neoplasms.